Newest class of nuclear submarine

The newest class of Sub Surface Nuclear Submarine (SSN) was introduced with the launch of HMS Astute by the British Royal Navy on 8 June 2007. This 7,800-tonne (8,600-ton) boat, with its Rolls-Royce PWR 2 pressurised water reactor for propulsion, will be capable of speeds in excess of 20 knots (23 mph; 37 km/h) underwater, and be able to go complete its designed service-life of over 25 years without refuelling. With four on order, this new class will represent the largest and most powerful attack submarines operated by the Royal Navy, and will be armed with Spearfish torpedoes and Tomahawk cruise missiles.